Medical endoprostheses or implants for a wide range of applications are known in a large variety from the prior art. Implants in the meaning of the present invention are to be understood as endovascular prostheses or other endoprostheses, for example stents, orthopedic implants, e.g. fastener elements for bones, for example screws, plates or nails, surgical sutures, intestinal staples, vascular clips, prostheses in the region of the hard and soft tissue, and anchor elements for electrodes, in particular of pacemakers or defibrillators.
Today, particularly frequently used as implants are stents which serve for the treatment of stenoses (vasoconstrictions). Stents have a body in the form of a tubular or hollow cylindrical basic grid which is open at both longitudinal ends. As an initial shape for such a body, hollow-cylindrical semifinished parts are usually used from which subsequently the basic grid is cut out, for example by means of laser.
Such an endoprosthesis having a tubular grid is inserted into the vessel to be treated and serves for supporting the vessel. Stents have established themselves in particular for the treatment of vascular diseases. By using stents, constricted regions in the vessels can be expanded resulting in a lumen gain. By using stents or other implants, an optimal vascular cross-section primarily necessary for the success of the therapy can be achieved; however, the permanent presence of such a foreign body initiates a cascade of microbiological processes which can result in a gradual blocking of the stent and in the worst case in a vascular occlusion.